Regulator for short circuit amperage on starting arc lights



N. K. CHANEY June 23, 1931.

REGULATOR FOR SHORT CIRCUIT AMPERAGE ON STARTING ARC LIGHTS Filed Ju ly 51, 1928 A TTO/BNE V5 I Patented June 23, 1931 NIT D .STATTES'PATENT OFFICE! NEWGOMB K. CHANEY, 01 LAKEWOOD, OHIO, ASSIGNOR T0 NATIONAL CARBON COM PANY, INC. A CORPORATION OF NEW YORK I REGULATOR FOR SHORT CIRCUIT AMPERAGE ON STARTING ARC LIGHTS Application filed July 31, 1928. SrialNo. 296,458.

This invention relates to electric arc lamps and is especially adaptable for use on the smaller type of such lamps made for burn ing at the lower amperages permissible on the ordinary lighting circuit. 7

To permit the safe use of the arc lamp in the home or similar li hting circuit it is necessary to provide sufiicient resistance in series with the arc to maintain an amperage within the limits of restriction usually imposed ,on such a wiring installation. At the same time in order to obtain the most efiicient results, especially in a lamp used for therapeutic purposes, it is desirable to operate the are at the highest possible amoperation is frequentlyrnecessary to insure continuous burning of the arc, especially in the smaller hand operated lamps, danger of blowing the fuses or overheating is often encountered.

The object of my invention is to provide means for regulating this short circuit amperage in such'a manner that a lamp may be safely started and operated at the maximum permissible current, and I have accordingly devised a mechanism which may be readily adapted to any type of arc lamp for use under conditions whereit is desirable that the starting current not greatly exceed that required for normal operation.

The advantages of this invention will be evident from a description of the accompanying drawing showing one modification as adapted to a parallel trim lamp.

The single figure, partly diagrammatic shows two carbon electrodes 1 and 2 held parallel to one another in suitable holders 3 and 4. Holder 4 is fixed whereas holder 3 is hinged to a permanently fixed bracket 5 and is movable about its point of support 6 by means of the extending lever 7 attached to holder 3. A rod 8 ,of insulating material having an enlarged" end or thumb-piece 9 is mounted in such a manner as to be free to move longitudinally a short distance against the action of a spring 10. Mounted ,on said rod is a collar 11, and a contact 12 normally held against coacting contact 13 byspring 10. A resistance 14 is in series circuit with the carbon electrodes and is also connected to the contact 12 by a shunt 15.

' The are may be started by pressing inwardly on the thumb piece 9 which in turn causes the collar 11 to exert pressure on the lever 7 and move the tip of electrode 1 toward electrode 2, said electrode 1 and attached lever 7 assuming the position shown by dotted lines. In moving the rod 8 to cause the electrodes to touch each other,

the contact 12 is removed from contact 13,

also shown by dotted lines, and the circuit is completed from the outside source of current through the line 16, the resistance 14:, and two electrodes, and out through the line 17. On releasing the thumb piece 9, the spring 10 causesthe ro'd'8 to move back into its normal position thus bringing together" the two contacts 12 and 13 and shunting out the resistance 14, through the shunt 15. At the same time the two electrodes are separated forming an arc;

The resistance 14 is thus'effective in lowering the circuit amperage only when the electrodes are touched together to start the arcand until the arc is of approximately the length required for normal operation at which time it is automatically shunted out of the circuit. Another resistance or current limiting means of suitable form, not shown in the drawing, is continually in series circuit with the electrodes and is suflicient with a normal operatingarc to maintain a current drain withinthe permissible range.

Any of the usual forms of electrical re"- sistance" may be used for the purpose of lowering the short circuit amperage but I prefer to makefsuch resistance atleast equal to or slightly greater than a the resistance of the arc of normal-"length in order) that the amperage on starting the arc will at no time exceed the current drain required for normal operation. If the are is to be burned only on alternating current a choke coil may be used in place of resistance 14- as a means of limiting the starting amperage and the permanent resistance likewise may be re placed with a choke coil. The contact or switch mechanism may also be of any desired form provided it is so constructed that it will operate to insert additional resistance or other current limiting means in the circuit when striking the arc and shunt out or disconnect the same when the arc has been drawn to the proper operating length.

lVhile I have shown my invention as adapted to a parallel trim lamp it is evident that with sli ht modifications it may be equally useful on a lamp of any type trim without departing from the spirit of this invention.

I claim:

1. An are lamp mechanism for regulating the short circuit amperage on starting an arc, comprising in combination a pair of electrodes, an electrical resistance in series circuit with said electrodes, a switch normal ly maintaining a shunt circuit around said resistance, and means for concomittantly moving the tipsof the electrodes together and operating said switch to open said shunt circuit.

2. An arc lamp mechanism for regulating the short circuit amperage on starting an arc, comprising in combination a pair of electrodes at least one of said electrodes being mounted for movement toward the other, an electrical resistance in series circuit with said electrodes, a switch normally maintaining a shunt circuit around said resistance, and a finger piece manually operable to move said electrodes together and simultaneously operate said switch to open said shunt circuit.

3. An arc lamp comprising electrodes mounted to separate by a predetermined distance and form an arc-gap when released; electrode-moving means operable to shorten the arc-gap; current limiting means in series circuit with the electrodes; a shunt around said current limiting means; and a switch in said shunt to be opened by said electrodemoving-means when the latter is activated to shorten the arc-gap.

4. An arc lamp comprising electrodes mounted to separate by a predetermined distance and form an arc-gap; a resistance in series circuit with said electrodes; a shunt circuit around said resistance; and electrode moving means manually operable to shorten the arc-gap and simultaneously open said shunt circuit.

5. An are lamp comprising electrodes mounted to separate by a predetermined distance and form an arc-gap when released;

NEWVCOMB K. CHANEY. 

